Field of the Invention
The present invention generally relates to audio processing systems, and more specifically to a dictation and recording system for moving vehicles exhibiting noisy environments.
Description of the Prior Art
Many professionals, including attorneys, doctors, accountants, sales people, and the like frequently find it convenient or necessary to dictate in a moving vehicle. Thus, routine letters or reports can be dictated during a lengthy automobile trip. Frequently, it is expedient to dictate in a vehicle immediately after having made a visit with a client, patient or potential customer when the facts are still clear and fresh.
While dictation in vehicles, such as automobiles, is an extremely common occurrence, no special provisions have been made for enabling dictation in a convenient manner which enhances the sound quality of the recorded audio to facilitate transcription.
Although modern combination radio and cassette or tape decks have reached a high level of sophistication and are provided with many features and functions, none of the known combination radio and cassette or tape decks are provided with a "record" function to allow the use of the radio cassette or tape deck as a dictation device in a manner which provides a satisfactory audio output suitable for transcription.
Dictation recording has generally been performed by the use of small, portable dictation machines, such as micro or mini cassette recorders. Portable, standard cassette recorders have also been used. There are significant disadvantages in using such portable units. To begin with, most are large, bulky and uncomfortable to hold and inconvenient to use. Because such small units cannot accommodate the sophisticated circuitry of desktop dictation equipment, the audio quality of such small, portable units is often inferior. Furthermore, the small units typically used in automobiles are, for example, battery operated. Such units represent a substantial outlay for batteries for the heavy user, and always present the possibility and likelihood that the charge on the batteries will become depleted at an inopportune time in the middle of dictation.
Thus, while very expensive, high fidelity radio and tape deck units are used in automobiles, these have not been effectively used to advantage for purposes of recording or dictation.
In U.S. Pat. No. 4,909,134, a combination transceiver and tape player and radio unit is disclosed. However, the patent merely discloses a radio/player combination which cooperates with a transceiver. The microphone shown is used to transmit over the transceiver. However, the microphone is not used to record onto a cassette which is placed into the radio/player unit.
In U.S. Pat. No. 4,388,712, an indicator is disclosed for use in connection with a combined radio/recorder for automobile use. While the patent states that the indicator can show the different operating conditions, including record, playback, etc., the patent does not teach the details of a dictation system or suggest the desirability for elimination of controllable or uncontrollable noises from the recorded dictation in order to enhance the sound quality of the recorded audio.
U.S. Pat. No. 4,737,976 discloses a radio telephone that uses two microphones to improve hands-free telephone control and dialing and speaker phone switching in mobile radio receivers. The patent addresses the problem for radio telephone communications where background noise may interfere with voice recognition and, therefore, automatic switching.
Japanese Patent Publication No. 56-107375 discloses a car stereo unit with recording capability, in which microphone recording, radio broadcast recording and microphone mixing during play is made possible without the use of a switch on the front panel of the unit. The specific mode of operation is controlled by contacts of a microphone jack connector. However, while insertion of the microphone jack disables the controllable radio output (broadcast audio), no provision is made for abatement of uncontrollable background or ambient noise.
Therefore, while abatement of "uncontrollable" ambient or background noise has been used in different environments and to achieve different purposes, the use of noise abatement techniques have not been applied to improve recording quality of dictation for transcription of dictation in moving vehicles.
For purposes of this invention, "controllable" noise or audio signifies any noise, audio or sound that can be controlled, abated or eliminated by the passengers in a motor vehicle. Such "controllable" noises include the output of a radio (turning the radio on or off), speech by passengers in the vehicle compartment (passengers stopping to talk), and the like. When "controllable" noises are totally abated, they are eliminated from the passenger compartment so that they are not present to be heard or to be picked up by a microphone in the passenger compartment. However, "uncontrollable" noise signifies any noise, audio or sound that cannot be controlled, abated or eliminated by the passengers in a motor vehicle. Such "uncontrollable" noises include ambient or background noises encountered mostly in moving vehicles, such as engine, wind and road noises. Traffic noise is another example of an "uncontrollable" noise.
Ambient of background noises, which are "uncontrollable" are almost always present in the passenger compartment of a moving vehicle and, while they can sometimes be reduced (e.g. closing of a window to reduce traffic noise), they can almost never be totally eliminated. Therefore, a microphone in the passenger compartment, such as used in portable dictating units, will pick up and record such "uncontrollable" ambient or background noises just as the passengers will always continue to hear such noises.